/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: FunctionMultiArgs.java,v 1.2.4.1 2005/09/14 20:18:43 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.functions;

import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.XPathVisitor;
import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;

/**
 * Base class for functions that accept an undetermined number of multiple
 * arguments.
 * @xsl.usage advanced
 */
public class FunctionMultiArgs extends Function3Args {
    static final long serialVersionUID = 7117257746138417181L;

    /** Argument expressions that are at index 3 or greater.
     *  @serial */
    Expression[] m_args;

    /**
     * Return an expression array containing arguments at index 3 or greater.
     *
     * @return An array that contains the arguments at index 3 or greater.
     */
    public Expression[] getArgs() {
        return m_args;
    }

    /**
     * Set an argument expression for a function.  This method is called by the
     * XPath compiler.
     *
     * @param arg non-null expression that represents the argument.
     * @param argNum The argument number index.
     *
     * @throws WrongNumberArgsException If a derived class determines that the
     * number of arguments is incorrect.
     */
    public void setArg(Expression arg, int argNum) throws WrongNumberArgsException {

        if (argNum < 3)
            super.setArg(arg, argNum);
        else {
            if (null == m_args) {
                m_args = new Expression[1];
                m_args[0] = arg;
            } else {

                // Slow but space conservative.
                Expression[] args = new Expression[m_args.length + 1];

                System.arraycopy(m_args, 0, args, 0, m_args.length);

                args[m_args.length] = arg;
                m_args = args;
            }
            arg.exprSetParent(this);
        }
    }

    /**
     * This function is used to fixup variables from QNames to stack frame
     * indexes at stylesheet build time.
     * @param vars List of QNames that correspond to variables.  This list
     * should be searched backwards for the first qualified name that
     * corresponds to the variable reference qname.  The position of the
     * QName in the vector from the start of the vector will be its position
     * in the stack frame (but variables above the globalsTop value will need
     * to be offset to the current stack frame).
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize) {
        super.fixupVariables(vars, globalsSize);
        if (null != m_args) {
            for (int i = 0; i < m_args.length; i++) {
                m_args[i].fixupVariables(vars, globalsSize);
            }
        }
    }

    /**
     * Check that the number of arguments passed to this function is correct.
     *
     *
     * @param argNum The number of arguments that is being passed to the function.
     *
     * @throws WrongNumberArgsException
     */
    public void checkNumberArgs(int argNum) throws WrongNumberArgsException {
    }

    /**
     * Constructs and throws a WrongNumberArgException with the appropriate
     * message for this function object.  This class supports an arbitrary
     * number of arguments, so this method must never be called.
     *
     * @throws WrongNumberArgsException
     */
    protected void reportWrongNumberArgs() throws WrongNumberArgsException {
        String fMsg = XSLMessages.createXPATHMessage(XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION, new Object[] { "Programmer's assertion:  the method FunctionMultiArgs.reportWrongNumberArgs() should never be called." });

        throw new RuntimeException(fMsg);
    }

    /**
     * Tell if this expression or it's subexpressions can traverse outside
     * the current subtree.
     *
     * @return true if traversal outside the context node's subtree can occur.
     */
    public boolean canTraverseOutsideSubtree() {

        if (super.canTraverseOutsideSubtree())
            return true;
        else {
            int n = m_args.length;

            for (int i = 0; i < n; i++) {
                if (m_args[i].canTraverseOutsideSubtree())
                    return true;
            }

            return false;
        }
    }

    class ArgMultiOwner implements ExpressionOwner {
        int m_argIndex;

        ArgMultiOwner(int index) {
            m_argIndex = index;
        }

        /**
         * @see ExpressionOwner#getExpression()
         */
        public Expression getExpression() {
            return m_args[m_argIndex];
        }

        /**
         * @see ExpressionOwner#setExpression(Expression)
         */
        public void setExpression(Expression exp) {
            exp.exprSetParent(FunctionMultiArgs.this);
            m_args[m_argIndex] = exp;
        }
    }

    /**
     * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
     */
    public void callArgVisitors(XPathVisitor visitor) {
        super.callArgVisitors(visitor);
        if (null != m_args) {
            int n = m_args.length;
            for (int i = 0; i < n; i++) {
                m_args[i].callVisitors(new ArgMultiOwner(i), visitor);
            }
        }
    }

    /**
     * @see Expression#deepEquals(Expression)
     */
    public boolean deepEquals(Expression expr) {
        if (!super.deepEquals(expr))
            return false;

        FunctionMultiArgs fma = (FunctionMultiArgs) expr;
        if (null != m_args) {
            int n = m_args.length;
            if ((null == fma) || (fma.m_args.length != n))
                return false;

            for (int i = 0; i < n; i++) {
                if (!m_args[i].deepEquals(fma.m_args[i]))
                    return false;
            }

        } else if (null != fma.m_args) {
            return false;
        }

        return true;
    }
}
